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Pollen may be key to more than just plant-life

Pollen found to combine with moisture to possibly produce clouds and rain.

Pollen not only seeds a future generation of plants and trees, but may seed the birth of clouds and rainfall, according to researchers from the University of Michigan and Texas A&M.

It was thought that pollen was too big to influence clouds, but when found that it broke down into fragments, pollen caused allergies. The same process could also seed clouds with rain, according to dailymail.co.

‘The grains were thought to be too large to be important in the climate system, too large to form clouds or interact with the sun’s radiation,’ said Dr. Allison Steiner U-M associate professor of atmospheric, oceanic and space sciences. ‘And also the large particles don’t last in the atmosphere. They tend to settle out relatively quickly.’

But Dr Steiner and her colleagues’ lack of faith that large particle theory held as clear evidence that pollen could not affect clouds only lead to more probing. The tests were conducted from the most popular sources of wind-driven pollen in the US: oak, pecan, birch, cedar and pine trees, as well as ragweed.

‘What we found is when pollen gets wet, it can rupture very easily in seconds or minutes and make lots of smaller particles that can act as cloud condensation nuclei, or collectors for water,’ said Dr Steiner. She added: ‘It’s possible that when trees emit pollen, that makes clouds, which in turn makes rain and that feeds back into the trees and can influence the whole growth cycle of the plant.”

As the research revealed that moisture can break pollen down, researchers proposed that clouds might also be affected by broken down pollen particles. But the way pollen interacts with our climate is still not fully known.

‘What happens in clouds is one of the big uncertainties in climate models right now,’ Dr Steiner added.
‘One of the things we’re trying to understand is how do natural aerosols influence cloud cover and precipitation under present day and future climate?’

There are plans underway to perform similar, more in depth studies regarding this field. Models will be aided with computer simulations on how the atmosphere interacts with plant life.